Until yesterday I used to search for unanswered questions with an "OR" search for some tags covering my expertise. Let's say
This is what shows at the right:
Since today any "OR" search seems to result in
0 results. Is this a deliberate change in the search engine? I can't find anything about it in Recent feature changes to Stack Exchange.
Maybe I should add that I specifically search this way to try and answer users that are currently waiting for answers. Searching with one specific tag does not show all candidate questions. This “OR” search in new questions is perfect for my purpose.